San Sebastián in Summer
In summer (June, July and August), San Sebastián sees average daytime highs around 30°C and overnight lows near 23°C, with 1022 mm of rain over about 84 wet days across the season. It is the 3rd-warmest season and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 30°C. The sky is clear or mostly clear about 3% of the time across summer, and the air most often feels oppressive.
Summer is San Sebastián's weakest season of the year to visit on our travel score. For the whole year in context, see San Sebastián's year-round climate.
- Avg daytime high
- 30°C
- 3rd-warmest season
- Avg overnight low
- 23°C
- Rainfall
- 1022 mm
- 84 wet days
- Avg wind
- 4 km/h
- Travel score
- 2.7
- weakest season of the year
- Months
- Jun · Jul · Aug
Temperature in San Sebastián in Summer
Across summer, daytime highs hold fairly steady around 30°C.
A typical summer day in San Sebastián reaches about 30°C and drops to 23°C overnight. The warmest of the three months is July, the coolest August.
How summer really feels in San Sebastián
Once humidity and wind are folded in, summer brings about 92 days that feel above 32°C and 0 that feel at or below 0°C.
The story in summer is heat — humidity pushes the afternoon "feels like" well above the raw temperature.
San Sebastián weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 31° / 21° | 18 | 4.9 | 11.2 | 5.3 |
| Feb | 32° / 22° | 15 | 3.8 | 11.5 | 4.8 |
| Mar | 33° / 23° | 36 | 8.5 | 11.9 | 4.0 |
| Apr | 33° / 23° | 94 | 14.4 | 12.3 | 3.2 |
| May | 32° / 24° | 351 | 27 | 12.7 | 2.6 |
| Jun | 30° / 23° | 374 | 28.4 | 12.8 | 2.6 |
| Jul | 31° / 23° | 287 | 27 | 12.8 | 2.8 |
| Aug | 30° / 23° | 361 | 28.6 | 12.5 | 2.7 |
| Sep | 30° / 23° | 456 | 29.2 | 12.1 | 2.6 |
| Oct | 30° / 23° | 384 | 27.7 | 11.7 | 3.0 |
| Nov | 30° / 23° | 116 | 15.5 | 11.3 | 4.4 |
| Dec | 31° / 22° | 27 | 6.1 | 11.2 | 5.4 |
Cloud cover in Summer
The sky is clear or mostly clear about 3% of the time across summer.
Chance of precipitation in Summer
San Sebastián gets around 1022 mm of rain over 84 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 4 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 12 h 48 min in early June to 12 h 18 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 5.4 kWh/m².
Hazard calendar for San Sebastián
In summer, San Sebastián overlaps its atlantic hurricane and rainy season season. The full year is below, with each hazard's peak months called out.
San Sebastián sits in the Atlantic hurricane belt; the season peaks August–October.
San Sebastián's rainy season runs May–October, when most of the year's rain falls.
Is summer a good time to visit San Sebastián?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a weaker month for outdoor sightseeing in San Sebastián.
What to pack for San Sebastián in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, San Sebastián sees daytime highs around 30°C and nights near 23°C. Pack light clothes and rain gear. Worth having: sun protection. About 84 days see rain.
Sea temperature near San Sebastián in Summer
The nearest coast averages about 30°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 49 km away) is warmest in July at about 30°C and coldest in February near 29°C.
The water stays above 20°C all year — warm enough for a swim any month.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 29 | 29 | 29 | 29 | 30 | 30 | 30 | 30 | 30 | 29 | 30 | 29 |
| Comfort | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical | Tropical |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 29 | Tropical |
| Feb | 29 | Tropical |
| Mar | 29 | Tropical |
| Apr | 29 | Tropical |
| May | 30 | Tropical |
| Jun | 30 | Tropical |
| Jul | 30 | Tropical |
| Aug | 30 | Tropical |
| Sep | 30 | Tropical |
| Oct | 29 | Tropical |
| Nov | 30 | Tropical |
| Dec | 29 | Tropical |
UV index in San Sebastián in Summer
Clear-sky midday UV across summer averages around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in San Sebastián peaks around March 21 at about 12 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 8 (very high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 9 | 11 | 12 | 12 | 11 | 12 | 11 | 11 | 11 | 10 | 8 | 8 |
| Level | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 9 | Very high |
| Feb | 11 | Extreme |
| Mar | 12 | Extreme |
| Apr | 12 | Extreme |
| May | 11 | Extreme |
| Jun | 12 | Extreme |
| Jul | 11 | Extreme |
| Aug | 11 | Extreme |
| Sep | 11 | Extreme |
| Oct | 10 | Extreme |
| Nov | 8 | Very high |
| Dec | 8 | Very high |
Air quality in San Sebastián in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in San Sebastián is worst in December — around 45 µg/m³ PM2.5 (poor), about 1.6× the cleanest month (June, 28 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 44 | 45 | 41 | 44 | 40 | 28 | 29 | 29 | 29 | 30 | 37 | 45 |
| Level | Poor | Poor | Poor | Poor | Poor | Moderate | Moderate | Moderate | Moderate | Moderate | Poor | Poor |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 44 | Poor |
| Feb | 45 | Poor |
| Mar | 41 | Poor |
| Apr | 44 | Poor |
| May | 40 | Poor |
| Jun | 28 | Moderate |
| Jul | 29 | Moderate |
| Aug | 29 | Moderate |
| Sep | 29 | Moderate |
| Oct | 30 | Moderate |
| Nov | 37 | Poor |
| Dec | 45 | Poor |
Where is San Sebastián?
San Sebastián sits at 14.6°N, 91.6°W, 313 m above sea level, in Guatemala. The nearest listed city is Retalhuleu, 4.0 km away.
Topography around San Sebastián
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Sebastián.
Within 3 km, the terrain around San Sebastián has only modest variations in elevation — a maximum elevation change of 150 m around an average of 314 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,200 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,178 m.
The land around San Sebastián is covered by trees (66%) and grassland (20%) within 3 km, trees (71%) within 16 km, and trees (53%) and water (20%) within 80 km.
Guatemala travel facts
- Travel advisory
- Level 3
- Reconsider Travel
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 43% of US
- price level, 2025
- GDP per capita
- $6,598
- 2025
- Happiness
- 6.5 / 10
- World Happiness, 2025
- Safe drinking water
- 49%
- of population, 2024
- Homicide rate
- 23.4
- per 100k, 2023
- Road deaths
- 22.9
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Moderate
- EF EPI 510
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Sebastián (14.5618°, -91.6487°, elevation 313 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.